Italian battleship Ammiraglio di Saint Bon

Ammiraglio di Saint Bon circa 1900

On 29 September 1911, Italy declared war on the Ottoman Empire in order to seize Libya.[7] Ammiraglio di Saint Bon initially served in the 3rd Division of the 2nd Squadron, but was later transferred to the Division of the Torpedo Boat Inspector, commanded by Rear Admiral Prince Luigi Amedeo.[8] The ship was not heavily involved in the fighting in North Africa in the first months of the war and, in December, was transferred to Italy.[9] On 13 April 1912, Ammiraglio di Saint Bon and the rest of the division sailed from Tobruk to the Aegean Sea to rendezvous with the 1st Division. The two divisions met on 17 April off the island of Stampalia, after which the combined fleet steamed north. The following day, the ships cut submarine telegraph cables between Imbros, Tenedos, Lemnos, Salonica, and the Dardanelles. They then steamed to the entrance to the Dardanelles in an attempt to lure out the Ottoman fleet. When the Ottoman coastal fortifications began to take the Italian ships under fire, the Italians returned fire and inflicted serious damage on them. On 19 April, Ammiraglio di Saint Bon and most of the fleet returned to Italy, leaving only Pisa, Amalfi, and a flotilla of torpedo boats to cruise off the Ottoman coast.[10]

On 30 April 1912, Ammiraglio di Saint Bon and the rest of the 3rd Division escorted a convoy of troopships from Tobruk to the island of Rhodes. The Italian heavy ships demonstrated off the city of Rhodes, while the transports landed the expeditionary force 10 miles (16 km) to the south on 4 May; the soldiers quickly advanced on the city, supported by artillery fire from the Italian fleet. The Turks surrendered the city the following day. While the Italian troops completed the conquest of the island, Ammiraglio di Saint Bon bombarded Ottoman positions in support of the Italian offensive.[11] Toward the end of May, the 3rd Division returned to Italy.[12] In July, Ammiraglio di Saint Bon and the rest of the division had withdrawn to Italy to replace worn-out gun barrels, along with other repairs.[13] By October, the Ottomans had agreed to sign a peace treaty to end the war.[14] After the war, Ammiraglio di Saint Bon had six searchlights installed on platforms abreast the funnels and the mast. A rangefinder was also added on top of the conning tower.[15]

In 1913, Ammiraglio di Saint Bon participated in an international naval demonstration in the Ionian Sea to protest the Balkan Wars. Ships from other navies included in the demonstration were the British pre-dreadnought HMS King Edward VII, the Austro-Hungarian pre-dreadnought SMS Zrínyi, the French armored cruiser Edgar Quinet, and the German light cruiser SMS Breslau. The most important action of the combined flotilla, which was under the command of British Admiral Cecil Burney, was to blockade the Montenegrin coast. The goal of the blockade was to prevent Serbian reinforcements from supporting the siege at Scutari, where Montenegro had besieged a combined force of Albanians and Ottomans. Pressured by the international blockade, Serbia withdrew its army from Scutari, which was subsequently occupied by a joint Allied ground force.[16]

Italy declared her neutrality after the outbreak of World War I in August 1914 but, by July 1915, the Triple Entente had convinced the Italians to enter the war against the Central Powers.[17] Nevertheless, the outbreak of war prompted Italy to retain Ammiraglio di Saint Bon and her sister, which had been scheduled for disposal in 1914–15.[15] The Austro-Hungarian Navy, Italy's traditional naval rival, was the primary opponent in the conflict. The Italian Naval Chief of Staff, Admiral Paolo Thaon di Revel, believed that an active fleet policy was prohibited by the serious threat from submarines in the confined waters of the Adriatic Sea.[18] Instead, Revel decided to implement blockade at the southern end of the Adriatic with the battle fleet, while smaller vessels, such as the MAS boats, conducted raids on Austro-Hungarian ships and installations. Meanwhile, Revel's capital ships would be preserved to confront the Austro-Hungarian battle fleet in the event that it sought a decisive engagement. As a result, the ship was not particularly active during the war.[19]

From the onset of Italian participation in the war, Ammiraglio di Saint Bon was used as a harbor defense ship in Venice, along with her sister and the old battleship Sardegna, as well as two cruisers and several smaller craft.[20] After April 1916, Ammiraglio di Saint Bon was used as a floating anti-aircraft battery to defend Venice. She continued in this role until the end of the war in November 1918.[15] The ship remained in the Italian Navy's inventory for only a short time after the end of the war; she was stricken from the naval register on 18 June 1920 and subsequently broken up for scrap.[1]